Antigenicity and immunogenicity of a novel, acute HIV-1 Tanzanian subtype C gp145 envelope protein for clinical development by Polonis V, Wieczorek L, Kalyanaraman V, Matyas G, Whitney S, Williams C, Tovanabutra S, Sanders-Buell E, Wesberry M, Ochsenbauer C, Chenine A, Rao M, Tong T, Alving C, Cheng H, Zolla-Pazner S, Michael N, VanCott T, Marovich M